Calculator

Solar Panel String Sizing Calculator

By NerdVolt Editorial TeamJune 16, 2026Estimate tool

Accuracy note: The arithmetic on this page is deterministic from your inputs. Solar production, code, utility, incentive, and savings outputs are estimates unless you supply exact equipment specs, tariffs, shade data, and local requirements.

Inputs

MPPT max voltage (V)MPPT min voltage (V)Panel Voc STC (V)Panel Vmp STC (V)Voc temp coefficient (%/°C)Vmp temp coefficient (%/°C)Lowest cell temp (°C)Highest cell temp (°C)

Result

How this is calculated

Max series modules = floor(max DC input voltage ÷ cold-corrected Voc). Min series modules = ceiling(MPPT minimum voltage ÷ hot-corrected Vmp).

Sources

NREL: PV module STC measurements